BERKLEY — More than four days after he was reported missing from his mother’s Padelford Street mobile home, the whereabouts of a 48-year-old Berkley man with developmental disabilities are still unknown.

Guilfoil said although the parking area of Myricks Air Field on Padelford Street no longer is crowded with law enforcement vehicles, police search-and-rescue personnel continue to search woods and local ponds for any sign of Donald Flint.

The initial search for Flint, who has been described as nearly non-verbal, began Thursday afternoon after his mother Nadine called to report him missing from their home, which is located across the street from the privately owned airfield.

Berkley Police Chief Scott Labonte said Friday that Flint, who worked part-time at Home Depot in Taunton, was known to occasionally wander off by himself, but never for so long or apparently so far.

Flint does not have a cellphone, nor does he wear a LoJack wristband or GPS device that could track his whereabouts, police said.

The initial search, besides officers with walking sticks in surrounding woods, included a state police helicopter, K-9 units, off-road ATVs and a horse-mounted unit.

SEMLEC dive team commander and Taunton police sergeant Matthew McCaffrey said he and five other SEMLEC divers were back in the water Sunday.

McCaffrey said the group spent five to six hours searching a man-made pond near a farm on Myricks Street, despite the fact that it’s not close by Flint’s home.

“We just want to make sure we can rule it out,” he said.

McCaffrey said he and others are concerned that Flint, who reportedly in the past has sometimes wandered away unclothed, might be at risk of hypothermia, notwithstanding daytime warm weather.

Anyone with information as to the possible whereabouts of Donald Flint are urged to contact Berkley Police Department at 508-822-7040.

Flint is described as a white man, 5-foot-10, 180 pounds with brown eyes, very fine gray hair and prominent ears.

There initially was some confusion as to when Flint was first reported missing.

A police source said his mother didn’t report him missing Wednesday night as was initially thought, but instead didn’t realize he was gone until Thursday afternoon.

A witness told police he’d seen Flint around 10 a.m. Thursday driving his tractor mower in circles, in a paved area in front of a large garage across the street from the entrance to the airfield, the police source said.

Police say Flint for many years was known to enjoy engaging in that particular activity.

The police source said Flint’s mother reportedly wasn’t home Wednesday night, when someone dropped off her son after working at The Home Depot, but that she did call and spoke to him to make sure he was OK.

It wasn’t until early afternoon Thursday that she realized he was not driving his tractor and was gone, the police source said.